JPS62141087A - Shielding adhesive material - Google Patents

Abstract

PURPOSE:To prepare a shielding adhesive material having a concealing property sufficient to shield corrected letters or the like and an overall thickness sufficient to prevent occurrence of a shade during copying. CONSTITUTION:A primer layer comprised of 65-85wt% titanium white and 35-15wt% vehicle resin and an adhesive layer are successively laminated on a base material. Vinyl chloride-vinyl acetate resin or a chlorinated polypropylene resin are preferred as the vehicle resin. The primer layer can be formed as follows. A primer is kneaded with an org. solvent, thereby dissolving the primer in the solvent. The soln. is applied on the base material to form a primer layer. It is preferred that the thickness of the primer layer after application be usually about 3mum or less. Examples of the base material include paper, particularly wood-free paper. Examples of the adhesive include a rubber adhesive and an acrylic adhesive.

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to a shielding adhesive for pasting to correction and correction areas of documents, etc., and more specifically to a shielding adhesive for pasting to correction and correction areas of documents, etc. However, the text underneath cannot be seen through,
The present invention relates to a shielding adhesive material (such as an adhesive tape or sheet) on which characters can be written and which does not cast shadows even when copied.

[Prior Art and Problems] Conventionally, various methods have been used to modify or correct documents written with ink or the like. The most common method is to physically remove 1Jli fibers from the paper by rubbing the correction area with an eraser, especially a sand eraser, with a rough surface. However, this method has problems such as the paper tearing and ink smearing when writing again.

Additionally, ink erasers are also commonly used. Although this method chemically erases ink, it causes discoloration of the paper during use and has the problem that it can only be used as ink for fountain pens.

Furthermore, in recent years, oil-based or water-based correction fluids or tapes have been widely used.

Among these, correction fluid is a paint-like substance made of white pigment and resin, and when used, the correction area is painted over with a brush, but this method is extremely complicated when there are many correction areas. Moreover, it is difficult to apply uniformly and flatly, and it takes a long time to dry after application.

On the other hand, tape is an extremely simple method that is simply pasted onto the corrected area, but there is a problem in that the corrected area can be seen through the tape base material (mainly paper) because it is usually extremely thin. For this reason, currently paper laminated with aluminum foil (for example, see Utility Model Application Publication No. 51-11046),
It uses paper coated with multiple layers of white ink. However, even with these tapes, the total thickness of the base material is inevitably thick, and therefore, when copies are made using a reflective copying machine, the outer periphery of the attached tape appears as a black line (the There is a problem called shadow.

[Object of the Invention] The present invention solves the above-mentioned problems, and provides a shielding material that has sufficient concealment properties for shielding corrected characters, etc., and has a total thickness (approximately 95 JL or less) that does not cause shadows to appear during copying. The purpose is to provide adhesive materials for

[Summary of the Invention] In order to achieve the above object, the present inventors conducted intensive research and found that by using an undercoat of a specific composition, the undercoat was impregnated by a simple surface coating method known in the art. It can be penetrated into the base material to the same extent as the treatment,
Furthermore, on the undercoat layer formed in this way,
The adhesive body obtained by providing the adhesive layer has sufficient hiding properties to cover corrected characters, etc., and can maintain a total thickness to the extent that shadows do not appear during copying, and the base material and adhesive They have discovered that the adhesive strength of the layers can be increased and have completed the present invention.

That is, the shielding adhesive of the present invention contains 65 to 85% by weight of titanium white and 35 to 15% by weight of vehicle resin on the base material.
It is characterized in that an undercoat layer consisting of the following and an adhesive layer are sequentially laminated.

The undercoat which is a component of the adhesive body of the present invention is titanium white,
and a vehicle resin.

The titanium white (Ti02) used here is known as an inorganic pigment, and has two different crystal structures: rutile type and anatase type, but rutile type is preferable in terms of hiding power. This titanium white has a lower specific gravity than other white pigments (anatase type 3.7-3.9, rutile type 4.1-4
．． 3) High coloring power and hiding power, and no reactivity. Furthermore, it is most suitable as an undercoat component for use in the present invention because it has good compatibility with resins and is unlikely to cause aggregation or phase separation.

Examples of vehicle resins include vinyl chloride-vinyl acetate resins, chlorinated polypropylene resins, acrylic resins, methacrylic resins, polyamide resins (for example, methanol-soluble methoxymethylated polyamides), polyvinyl acetate resins, polyester resins, and polyurethane resins. These can be used in combination of one or more types. Among these resins, vinyl chloride-vinyl acetate resins or chlorinated polypropylene resins are preferred, and those with a glass transition temperature of 50°C or higher and a degree of polymerization of 10
0 or more, preferably 300 or more, and has a copolymerization ratio of 85 to 98% by weight of vinyl chloride, 2 to 15% by weight of vinyl acetate, and optionally contains 0 to 15% by weight of polyvinyl alcohol. Vinyl acetate resin or chlorine content of 20-35% by weight, melting point of 85-1°O
Chlorinated polypropylene resins that are oC are preferred.

The blending ratio of titanium white and vehicle resin in the undercoat is 15 to 35% by weight/65 to 85% by weight, preferably 20 to 30% by weight/70 to 80% by weight. If the blending ratio of the vehicle resin is 15% by weight, a part of the titanium white will not be mixed with the vehicle resin and a portion of only the titanium white will be formed, which will not only make it impossible to obtain a uniform system as an undercoat, but also increase the strength of the film. There is a possibility that the primer will peel off from the paper due to scratching or bending. Also, 30
If it exceeds Jujaku%, the viscosity of the primer increases and its permeability decreases, forming a film on the surface of the paper, and the pigment concentration decreases relatively, making it impossible to obtain sufficient hiding power. .

The undercoat layer can be formed by adding the undercoat into an organic solvent, kneading and dissolving the mixture, and then applying the mixture onto the base material.

The organic solvents used here include methyl alcohol,
Alcohols such as butyl alcohol, ketones such as acetone and methyl ethyl ketone, aliphatic and aromatic hydrocarbons such as n-hexanes, cyclohexane, heptane, mineral spirits, toluene and xylene, ethyl acetate,
Esters such as butyl acetate can be mentioned, and one or more of these can be used.

The primer is prepared by adding titanium white and vehicle resin into an organic solvent at the same time or one after the other, then ball milling,
It can be obtained by kneading with a sand mill or Miki roll.

However, when using a ball mill or sand mill, the total solids concentration in the processing agent should be about 30% by weight, and when using a triple roll, it should be at least 30% by weight to increase the kneading effect. This is preferable because it can be done. Also,
The obtained primer has a standard viscosity of 5 to 1 oOcp (
20° C., total solids concentration 30% by weight).

Furthermore, if necessary, a waterproofing agent, a stabilizer, a blocking agent, a dye, etc. can be added to the undercoating agent within a range that does not impair its performance.

Next, the basecoat sub-solution thus obtained is applied onto the substrate.

The substrate used here may be paper, especially wood-free paper. This high-quality paper is a type of printing paper, and is most preferable as a base material for the adhesive because it has good texture and is opaque, but it is of course not limited to this and is suitable for the purpose of the present invention. It can be anything. However, those subjected to seepage prevention treatment or excessive size treatment are not preferable because it is difficult for the primer to penetrate sufficiently. If paper is used as the base material, it should have a basis weight of 75 g/m or less and a thickness of 90 W to increase the permeability of the processing liquid and the hiding effect of the adhesive, and to eliminate shadows from copying. The following are preferred.

No special method is required for applying the undercoat onto the base material, and conventional methods such as surface coating methods using a gravure coater, a mare bar, a cool coater, an air knife coater, etc. can be used.

Since the primer of the present invention has extremely good permeability, it can penetrate not only the surface of the substrate but also the inside of the substrate and even the reflective surface of the coated surface of the substrate even by a surface coating method. The same effect as the impregnation method can be obtained.

The thickness of the undercoat layer after coating is preferably approximately 3 μm or less.

After forming the undercoat layer in this way, 50 to 10
Drying is performed at 0°C for 20-300 seconds.

An adhesive is then applied onto this primer layer.

The adhesive used here includes known adhesives such as natural rubber, imprene rubber, styrene-butadiene rubber, styrene-isoprene block polymer, polyisobutylene rubber, rosin resin, and terpene resin as tackifiers. , rubber-based adhesives to which resins such as terpene phenol resins and petroleum-based resins are added; acrylic adhesives such as (meth)acrylic acid esters; and the like.

These adhesives can be made into removable or strongly adhesive (permanent) adhesives by adjusting the degree of polymerization and crosslinking of the polymer compounds that constitute them. In addition, by using adhesive microspheres (for example, a polymer of (meth)acrylic acid ester obtained by suspension polymerization) as a constituent component, it is possible to create an adhesive with better removability. .

The adhesive is applied by a conventional method such as a knife coater, a reverse roll coater, a gravure coater, or a gravure coater. Alternatively, a transfer method can also be used in which a pressure-sensitive adhesive is applied to a release paper, dried, and then bonded to a base material.

The coating thickness of the adhesive can be changed as appropriate depending on the desired adhesive properties, etc., but in order to prevent copying shadows, the amount of adhesive applied should be adjusted so that the total thickness of the adhesive is 95 mm or less. There is a need.

[Effects of the Invention] As explained above, the adhesive body of the present invention has an undercoat layer and an adhesive layer on a base material, and since the undercoat used in the present invention has extremely good permeability, It is possible to sufficiently penetrate not only the surface of the substrate but also the inside of the substrate by a simple surface coating method without using complicated methods such as impregnation treatment. For this reason, the thickness of the undercoat layer formed on the base material can be made extremely thin, and as a result, the total thickness of the adhesive body can be reduced to a level where the shadow of the copy does not appear while maintaining excellent hiding properties. It is very useful as an adhesive for modifying or correcting documents, etc.

[Examples of the Invention] Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not particularly limited by the Examples.

In addition, 1 part J and "%" in the examples are all "
"parts by weight" and "% by weight".

Example 1 6 parts of vinyl chloride-vinyl acetate resin (trade name: Denkabinyl #1O00GKT, manufactured by Denki Kagaku Kogyo Co., Ltd.) was dissolved in 70 parts of ethyl acetate. Next, rutile type titanium white (trade name TCA-555 manufactured by Tohoku Kagaku Co., Ltd.) 2
4 parts were added and mixed and ground in a sand mill for 15 minutes. The solids concentration of the primer solution thus obtained was 30% by weight, and the viscosity was 40 centipos 1'(20'C). Without diluting this, apply it to one side of a tape-shaped high-quality paper with a basis weight of 70 g/m' using a gravure coater for 20 minutes.
g/m" to form an undercoat layer. The thickness at this time was 86 l (paper thickness: 85 l). Also, the undercoat penetrated into the side opposite to the coated side of the paper. was observed. Next, an acrylic adhesive (trade name) was applied on the undercoat layer.
Olipine BPS-2993D (manufactured by Toyo Ink Co., Ltd.) was applied to a thickness of 9 ml, laminated with silicone-treated release paper, and wound up to obtain a tape-like adhesive.

I drew a line about 1 inch wide on high-quality 45 kg paper with a black oil-based pen (registered trademark Magic Ink), pasted the tape-like adhesive on top of it, and made a reflective copy, and the ink line was , it was completely shielded and there was no so-called copy shadow at the edge of the tape.

Example 2 j! ! Vinyl chloride-vinyl acetate resin (Denkavinyl #1
9 g of 000AS (manufactured by Denki Kagaku Kogyo Co., Ltd.) was heated and dissolved in 70 g of a mixture of toluene and ethyl acetate l:1i. To this was added 21 g of rutile type titanium white (trade name: TCA-555 manufactured by Tohoku Kagaku Co., Ltd.), and the mixture was mixed and ground for 20 minutes using a sand mill. This primer solution has a solid content concentration of 30
%, and the viscosity was 55 centivoise (20'C). This was coated with a gravure coater to form a tape with a weight of 70 g/m. It was applied to one paper at a rate of 20 tr/m" to form an undercoat layer. Furthermore, on the opposite side to the undercoat layer, a long chain alkyl acrylate copolymer was coated with '
A release agent was applied. The adhesive is U.S. Patent No. 369114.
The hanging g:J polymer of polyacrylic acid ester described in No. 0 was coated on the undercoat layer at a dry weight of 5 g/m' and wound up into a roll to obtain a tape-like adhesive body. The thickness at this time is 87. The total tape thickness was 921L.

When the same test as in Example 1 was carried out using this, there was a sufficient concealing effect and there was no copying shadow. Furthermore, this tape could be easily removed after copying, and there was no adhesive residue or paper smudge.

Example 3 11A hydrogenated polypropylene resin (trade name Birdren I)
6 parts of IL (manufactured by Toyo Kagaku Co., Ltd.) was heated and dissolved in 70 parts of toluene. Rutile type titanium white (product name TCA)
24 parts of -555 (manufactured by Tohoku Kagaku Co., Ltd.) were added and mixed and ground in a ball mill for 12 hours. The solid content concentration of this primer solution is 30% by weight, and the viscosity is 30 centivoise (2
0'C). This is tsubo N 70 g/m'
After coating on a tape-shaped high-quality paper, the same adhesive as in Example 1 was applied, a release paper was laminated thereon, and the adhesive was wound up to obtain a tape-shaped adhesive body. The thickness at this time was 86 mm, and the total tape thickness was 95 mm. Met.

When this was subjected to the same test as in Example 1, a sufficient shading effect and no copy shadow appeared.

Comparative Example 1 Acrylic adhesive (trade name Olivine BPS-299
3D (manufactured by Toyo Ink Co., Ltd.) was applied to a thickness of 10 mm.

The total thickness of the tape at this time was 95 mm. When this was subjected to the same copying test as in Example 1, the lines of quick-drying ink were visible through the copy paper, and no shielding effect was obtained.

Comparative Example 2 15 parts of vinyl chloride-vinyl acetate resin (trade name: Denkabinyl #1OOOGKT, manufactured by Denki Kagaku Co., Ltd.) was heated and dissolved in 70 parts of ethyl acetate. To this was added 15 parts of rutile type titanium white (trade name: TCA-555 manufactured by Tohoku Kagaku Co., Ltd.), and the mixture was mixed and ground in a sand mill for 15 minutes. This solution has a solid content concentration of 30% by weight and a viscosity of 200 centivoise (2
0°C). This was coated with a gravure coater with a basis weight of 70.
g/m' tape-like high-quality paper at a rate of 7 g/m''.The total thickness at that time was 86 tiles.The acrylic adhesive used in Example 1 was applied to this tape at a final thickness of 9 g/m''. When a copying test similar to that in Example 1 was conducted using this adhesive, lines of quick-drying ink were visible in both samples, and a sufficient shielding effect could not be obtained.

Claims (4)

[Claims] (1) A shielding adhesive, characterized in that an undercoat layer and an adhesive layer each comprising 65 to 85% by weight of titanium white and 35 to 15% by weight of a vehicle resin are laminated on a base material. (2) The adhesive body according to claim 1, wherein the vehicle resin is a vinyl chloride-vinyl acetate resin or a chlorinated polypropylene resin. (3) The adhesive body according to claim 1, wherein the adhesive is a removable adhesive. (4) The adhesive body according to claim 1, wherein the adhesive is a strong adhesive type adhesive.